Sod harvesting machines are generally mounted upon a tractor for movement across a field to be harvested. The sod harvesting machine includes a cutter blade which is guided by the machine to cut across the sod under the upper surface of the ground to a required depth and to a required width to form a continuous sod strip which is carried from the cutting blade on an inclined conveyor upwardly and rearwardly of the cutting blade for folding and collection.
A further cutting element adjacent the cutting knife is provided for severing the continuous sod length into separate sod pieces to enable them to be reasonably stacked and handled generally by manual process.
A first type of a machine known as a "slab machine" acts to simply fold the sod piece in two about a fold line transverse to the length of the sod piece at the mid point of the sod piece so that two lengths are folded to face inwardly.
In a second type of the machine, the sod pieces are rolled so that the forward edge of the sod piece starts the inside of the roll and then as the sod piece is forwarded along the conveyor the roll is continued at a fixed location along the length of the conveyor until the trailing edge reaches the roll whereupon the roll is released to be stacked in roll form.
It is of course necessary to properly handle and stack the sod pieces as they are released from the conveyor. Up till now the stacking of the sod pieces has been carried out wholly by hand. For this purpose the tractor carries at the rear of harvesting conveyor a pallet support system for receiving a pallet onto which the sod pieces can be stacked. Alongside the pallet is arranged a platform on which the labourer stands. The labourer is then required to grasp each sod piece as it is presented by the harvesting machine and to manually lift that sod piece and transfer it onto the pallet. Slabs are of course laid side by side across the pallet. In most examples a slab for manual handling is preferably 48 inches by 24 inches so that when folded it is 24 inches by 24 inches thus constituting one quarter of the surface of a four foot square pallet. Smaller slabs are possible and often 16 inch wide harvesting machines are used so that in this case three such slabs are arranged across the width of the pallet. When stacking rolls, the rolls are arranged in a row in a first direction across the pallet and then the direction is rotated through 90.degree. for a second row of rolls thus forming a stable stack. Again twenty four inch rolls are possible in which case two rolls side by side fill the width of the pallet. Sixteen inch rolls require three such rows to fill the width of the pallet.
However as stated above up till now this stacking process has been carried out wholly manually which is a very tiring and unpleasant task bearing in mind that the sod pieces can be very dusty and bearing in mind that as much as fifty tons can be harvested in a single day. However up till now the complexity of handling the sod pieces has required the manual dexterity of a human labourer to grasp and handle the different type of sod pieces without allowing the structure of the slab or roll to become deformed and to enable a proper stack to be formed.